Spabk-blug foe



1. M VALLEY AND B. MARCOTTE.

SPARK PLUG FOR EXPLOSIVE ENGINES.

APPLICATION FILED MAY 29 I919.

Patented Nov. 4, 1919.

.spark plugs for ignitii'ig '.=Thcmain start.

ReitENT OFFICES JOHN I i'UlSCQ VALLEY AND BAHLOVT MARCOTTE, OF CHICAGO, ILLINOIS.

SPARK-PLUG.- FQR EXFLQSIVE-ENGINEfi.

insecure Application filed May 29, 1919. Serial No. 300,572.

To all whom may concern:

Be it known that we, loan Mnsoo VALLEY and BARLOW 'lvlirnco'r'rc, citizens of the United States, and residents of Chicago. in the county of Cool: and State of Illinois, have jointly-in ented certain new and useful 1mproi'ements in Sparlellugs tor Explosivelfingines; and we do hereby declare that the following description of our invention,

taken in connection with the accompanying sheet of drawin forms a full, clear and exact specification. which will enable others skilled in the art to which the said invention appcrtains to make and use the same.

This invention has gel'leral reference to charges in internal combustion engines; and it consists. essentially in the novel and peculiar combination of parts and details of construction. as hereinafter first fully set torth and described, and then pointed out in the claims.

The object of this inyentioi'i is the produ'ction of an etlicient. serviceable, and comparatiycly inexpensive spark plug, which can be readily applied to. and removed from, the motor Ifor cleaning and renewal pur-. poses. Other obiects of this invention will hercii'iaiter appear.

in the drawings 'lo'rming a part of this spccitication -higore 1" is an elevation of this spark plu j. Fig. "l a longitudiimlsetiional elevation of thesame.

A. in these drawings designates the metallim'main body. of this spark plug. It is preferably. of hexagonal contour. to permit of the application of a suitable wrenclu as shown in the figures at 12. the lower portion of which body is reduced in uiameter. as at 13. and externally scrcw-threaded. as at ll,

to thiconventional size and niunbcr of threads to the inch, to fit into. and engage. the openings in the engine cylinders; tapped to receive the same. The upper end of this main body A likewise. reduced in diaof the nut, B being filled with packing C,

"specification of itetters Patent. I

the explosive 1 shown in Fig.2.

Patented Nov. 4, 19919.

preferably of asbestos or other non-coinbus--- tihle. but somewhat elastic material.

1n the bore 16, and pro1ectiug from both ends of the body A. there is located a core 1), of vitreous material, such as glass, porce lain, and the like. This core is centrally and longitudinally bored throughout, to receive a metallic electrode E, which electrode is long enough to protect from both ends of said core. its upper end being externally screw-threaded to engage a cap Fi located at the upper end of the core D, and pro ject therefrom toreceiye" a thumb, or bind lug, nut :20, which connects ont 'nd' at an electricconductor :21, to the electrode l ;The core, D has within the enlarged-bore 18 of the 'main'body A an annular collarwhich bears upon the shoulder 19 aforesaid; and spaced therefrom there is near the lower end of said core D, a sccond collar which bears upon the shoulder 17 at thelowcr end of the bore .16. Beneath this collar there is preferably placed an elastic, non-co'mbus tible washor iZl; i

From the lower end of the body A extends a second electrode (l. which is in 'metallic contact with the body A; which latter body. a

when installed in an engine cylinder. forms one of the two" poles of an electric circuit. This second electrode has its free endbent at right angles. and asshown in the figures of the drawings. this "end reachesrto within.

a predetermined distance of the lower end of the electrode E. either at the sidethcreot.

as illustrated )in Fig. 1. ojr'a predetermined distance below the same. indicated at 25.

in Fig 2.to afford the required spark gap. either construction hcingcttective and perfectly satisfactory,

While we prefer the direct connect the electric condutcorto the electrode on of E. as

structionlhyemploying spring iack-c tjof usual construction, .This clement ;2 3.-; as shown in Fig 1'. I'FPillSllttl o elnthuncclt 27;. formed 'in the .a'pvF'. and carries ajbi -uliug we may n-iodify this con post by w hiclrtho electric conductor-.121;

is secured-to the jack- 26.

it may now lie-noted'that there is in the body A a wide space between the interior wall of the-hody Aand the exterior of the corelh or in other words, thohore 16 m the body A c01'is1derably larger m tllan'ieter than the do amcter of the core l), which prevents possible contact-mg Wlill-EtlCll other. The coetlicicnt ot expansmn of the body A is slightly greater than that of the core D, so that, in view of the fact that the body ,A expands longitudinally in upward and downward directions, but mostly upwardly, because-the lower end of the body is fixedly connected to the engine cylinder, this slight upward movement will have a tendency to slightly lift the core by its collar 22, not enough, however, to endanger this collar and cause it to snap off the main portion of the core. This lifting of the core will cause a very slight upward movement of the collar 23 from the shoulder 17, and thereby prevent any possible damage to said collar by the expansive force of the parts. At the same 1 time, the elastic washer 24 below the collar 23 prevents oil, grease, or carbon to enter the space 16, so that fouling is practically eliminated. terminals ofthe electrodes can be readily removed in the usual manner.

Having thus fully described our invention, we claim as new, and desire to secure by Letters Patent of the UnitedStates 1. A spark plug for explosive engines and the like, comprising, in combinatiom'a metallic ma 11 body, said body having a longttudinal axial bore th rbughout, the lower end of said bore being contracted to alford, a shoulder'thereat. the upper end of said bore being enlarged to ail ord a second shoulder in said metallic bod both of said-shoulders being in ,the saine upward direction, a core .of vitreous material. in said bore, said core being round and of the same diameter throughout, said core being considerably smaller in diameter than the bore in said main body, there being on said core approxifitely medially of its length, an annular l i 0. ar, constructed to bear upon the shoulder inthe enlarged bore, there being on said core near its lower end a second annular collar constructed to bearnpon the shoulder formed by the contracted portion of said bore, said core being integrally formed with said collars, said core having an axial bore throughout its entire length, an electrode in the latter bore, said electrode projecting from both ends of said core, the upper end of said electrode being externally screw-threaded l clamping nut on said screw-threaded portion, a metallic cap at the upper end of said core to which said electrode is fixedly conuocted, an electric conductor secured to said (top by said clamping nut, and asecond electrode secured to said main body and reach- Any carbon collecting at the ing within a predetermined distance of the lower end of said first-mentioned electrode to afford a spark gap between said electrodes.

2. A spark plug for explosive engines and the like,,comprising, in combination, a main, metallic body, said body having'an axial bore throughout, the lower end of said bore being contracted to afford a shoulder thereat, the upper end of said bore being enlarged to afford a second shoulder near the upper end of main bore, both of said shoulders facing in an upward direction, a core ofwitreous material in said bore, said core being round and of the same diameter hroughout, said core being considerably smaller than the bore of said main body, there being on said core approximately medially of its ltngth, an annular collar located iii the enlarged space of the main body and bearing upon the shoulder therein, there being on said core near its lower end a second annular collar fitting the bore of said main body and bearing upon the shoulder formed by thecontraction of said bore, said core being integrally formed with said collars, said core having anaxi'al bore throughout its length, an electrode in the latterbore, said electrode projectin from both ends of said cdre, the upper en of said electrode being externally screw-threaded, a clamping nut on said screw-threaded portion, a metallic said electro e is-fixedly connected, an electric conductor secured to said cap by said clamping nut, a second electrode in metallic contact with said main body and reaching within a predetermined distance of the lower terminal of said first-mentioned electrode to afiord a spark gap therebetween, there being at the upper end of said metallic body a reduced, externally screw-threaded portion, a recessed nut in engagement with said latter portion, a non-combustible elastic packing in said nut and said enlarged bore and bearing 11 on the upper face of the firstmentioned co lar, and an elastic, non-combustible washer between the lower face of the second-mentioned collar and the shoulder at the lower end of said bore in the main y i e In test mony that we claim the foregoing as our ]01Ill; invention we have hereunto set JOHN MU SCO VALLEY, BARLOW MARCOTTE.

our hands.

, cap at the "u per end of said core to which 

